Craniofrontonasal syndrome is an X-linked syndrome which is more severe in females than males. Often males will have only hypertelorism

Hypertelorism

Hypertelorism is an abnormally increased distance between two organs or bodily parts, usually referring to an increased distance between the orbits . In this condition the distance between the inner eye corners as well as the distance between the pupils is greater than normal...

 (far apart eyes), whereas females have frontonasal dysplasia

Dysplasia

Dysplasia , is a term used in pathology to refer to an abnormality of development. This generally consists of an expansion of immature cells, with a corresponding decrease in the number and location of mature cells. Dysplasia is often indicative of an early neoplastic process...

, craniofacial asymmetry, bifid nasal tip, grooved nails, wiry hair and anomalies of the thoracic skeleton.

Most cases arise from mutations in the gene

Gene

A gene is a molecular unit of heredity of a living organism. It is a name given to some stretches of DNA and RNA that code for a type of protein or for an RNA chain that has a function in the organism. Living beings depend on genes, as they specify all proteins and functional RNA chains...

 for EFNB1

EFNB1

Ephrin-B1 is a protein that in humans is encoded by the EFNB1 gene.Mutations in this protein are responsible for most cases of craniofrontonasal syndrome.-Further reading:...

.